Fix a bit of libc++-specific behavior in the regex tests; add a missing test. Reviewed as https://reviews.llvm.org/D57391 Thanks to Andrey Maksimov for the patch

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@352781 91177308-0d34-0410-b5e6-96231b3b80d8

test/std/re/re.alg/re.alg.replace/exponential.pass.cpp

@@ -0,0 +1,38 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <regex>
+// UNSUPPORTED: libcpp-no-exceptions
+
+// template <class OutputIterator, class BidirectionalIterator,
+//           class traits, class charT, class ST, class SA>
+//     OutputIterator
+//     regex_replace(OutputIterator out,
+//                   BidirectionalIterator first, BidirectionalIterator last,
+//                   const basic_regex<charT, traits>& e,
+//                   const basic_string<charT, ST, SA>& fmt,
+//                   regex_constants::match_flag_type flags =
+//                                              regex_constants::match_default);
+
+#include <regex>
+#include <cassert>
+
+#include "test_macros.h"
+
+int main()
+{
+    try {
+        std::regex re("a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?a?aaaaaaaaaaaaaaaaaaaa");
+        const char s[] = "aaaaaaaaaaaaaaaaaaaa";
+        std::string r = std::regex_replace(s, re, "123-&", std::regex_constants::format_sed);
+        LIBCPP_ASSERT(false);
+        assert(r == "123-aaaaaaaaaaaaaaaaaaaa");
+    } catch (const std::regex_error &e) {
+      assert(e.code() == std::regex_constants::error_complexity);
+    }
+}